Strainer



Nov. 1, 1932. R, G. MARTER 1,885,850

STRAINER Filed April 20, 1951 .2 Sheets-Sheet l NOV. 1, 1932. R, G, MARTER 1,885,850

STRAINER Filed April 20. 1951 2 Sheets-Sheet 2 E/VSWE 7.

Patented Nov. 1, 1932 Y RICHARD MARTER, OF MILWAUKEE, WISCONSIN, ASSIGNOR TO NATIONAL ENAMELING &: STAMPING COMPANY, OF MILVAU'KEE, VJISCONSIN STRAINER Application led April 20, 1931.` Serial No. 531,318.i

This' invention pertains to strainers, and while the same is applicable to many uses, it is particularly designed for strainingmillr.

In strainers of the foregoing character, it

`51 is customary to provide a funnel with a perforated bottom upon which a strainer cloth of felt or other suitable material is held byV a perforated retaining disc. Screens have been employed, but these are impractical, due to iothe fact that they lack durability and soon become distorted. In instances where perforated plates are employed, it often occurs that the retaining disc is so positioned as to cut oft' the openings in the bottom of the funnel or hopper, which results in materially retarding the flow of liquid.

l It is, therefore, primarily the object of the present invention to provide a strainer of the foregoing character, in which the perfora- M. tions in the retaining plate and strainer bottom are so spaced and proportioned as to insure a'substantially uniform area of opening, regardless of the relative position of the two, thus obtaining a predetermined flow of liquid at all times. l

Incidental to the foregoing, a more specific object of the invention resides in the provision of a strainer including a pair of round perforated plates superimposed upon each 3o other, one of said plates having elongated arcuate perfo-rations, and the other of said plates having evenly spaced perforations of smaller area and in circumferential alignment with the perforations on the first mena', tioned plate, toprovide a substantially uniform area of opening through the two, irrespective of their relative positions.

A more specific object resides in forming the elongated openings in one of the members 4o in a plurality of circumferential groups or series, the openings of the inwardly successive rows 1n each series being reduced in length, while-the openings m the other of said members are substantially uniform and of 43 less area. l In addition to the foregoing, av still further object resides in forming perforations in both members of the strainer in radial disalignment and of substantially uniform circ cumferential spacing to provide an approximately uniformamount of stock throughout any radial 'cross section to preventuneven. weakening of ythe material with resultant warping or breakage.

' 1With the above and other objects in view, which will appear as thefdescription'proceeds, the invention resides in the novel construction, combination and arrangements of partssubstantially as hereinafter described andmore particularly defined by the appended claims, it being understood that such changes iny the precise embodiment of the herein disclosed invention may be made vas come within the scope of the claims. v

In the accompanying drawingsl is illustrated one complete example ofthe physical embodiment of the present inventionfcon- Y structed according to the bestv mode so Vfar devised for the practical application ofthe principles thereof. Y

In the drawings, Figure 1 is avertical section taken through a strainer constructed in accordance with the present invention;

Figure 2 is a plan section taken on theline 2-2 of `Figure 1,parts being broken away to more clearly illustrate structural features;

Figure 3 is an enlarged fragmentary detail of the same; and c j Figure 4 is a fragmentary detail of the perforated bottom plate of the funnel, i

v Referring now more particularly to the accompanying drawings, the numeral ldesignates a funnel provided with an annular restricted lower portion 2 having secured thereto in any suitable manner a perforated bottom plate 3. f In practice, a strainer pad All: of cloth, felt, paper, or other suitable material, is positioned on the-bottom plate 3, and held thereon by a perforatedretainer plate 5, which for the convenience of manipulation is provided with a suit-able handle 6. Obviously, the retainer plate 5 serves to effectively hold the strainer cloth l in intimate contact with theperforated bottom plate 8, thus insuring all of the liquid passing through the strainer cloth.

AseXplainedin the preceding objects difficulty has been encountered heretofore in obtaining a predetermined uniform flow of liquid 'through conventional strainers,`due

to the fact that unless extreme care was employed in properly positioning the retainer plate with relation to the bottom strainer plate, the perforations or openings in the strainer plate would be cut off, thus retarding the flow. f

. To overcome the foregoing, the present invention provides for a novel formation and arrangement of openings in the strainer and retaining plates to provide for uniform flow of liquid therethrough, regardless of the rel- 'radually reducedin length to provide a uniform number of connecting webs between the perforations. At the same time it will be noted that the openings of each row are radially disaligned, thus providing for an approximate uniform amount lof stock on any radial cross section. r

The purpose 'of grouping the openings in rows gradually reduced in length is to maintain the elongated formation of the openings throughout the radius of the plate, it being otherwise obvious that were therows of openings to besuccessively reduced in length, toward the center of the plate, those approximatethe center would have to be restricted to such extent as to vbe ofY approximately the areafof the openings inthe retainer plate, which would defeat'the purpose .of theinvention.

` In the exemplification'cofV the invention` illustrated, a third series or group ,e,of perforations is provided adjacent the center o f the plate, which are of substantially uniform elongation,` the innery row;I being provided withfewer perforations than 'the outer row of the group Iin orderto prevent excessive weakening of the stock at thisy point. Y

'Asl shown in the drawings, the 'retainer plate 5V is provided with aY plurality of openings 8v which in the present instance are round, although the same may be of any concentric formation, such as square, hexagonal,

and the like, it being understoodthat the perforations V8 'are substantially uniform in area and. spacing, the samebeing disaligned ra'- dially but aligned circumferentially toalign with thepcircumferential rows of openings 7 in the bottom plate 3. Y

As` best indicated in Figure 3, dueto'the circumferentialelongation of theslot 7 apred'etermined area of? opening between the plates, Sand 5 is obtained, regardless of. the

` relative position of the plates, thus eliminating the necessity of carefully positioning the retainer plate and insuring a uniform flow of material through the strainer at all times.

The foregoing is due to the fact that the relative proportions of the openings in the respective plates is such that while a certain portion of the elongated openings may be cut off by the connecting webs in the adjacent plate, a. sufficient portion of the slots remains exposed or aligned with the openings in the adjacent plate-to insure a uniform predetermined flow.

From the foregoing explanation taken in connection with the accompanying drawings it is belived that the advantages of the present structure will be quite apparent, in that not only is a uniform flow of liquidthrough the strainer provided for, regardless of the respective positions of the perforated plates, butalso theperforations are so formed and spaced as to eliminate uneven weakening of the plate, which is highly important ina device of the present character, due to the fact that the same receives exceedingly rough usage, which would otherwise cause the perforated plates to bend or warp, thus preventing the intimate contact between the plates and filter cloths,fessential to the operation of a strainer of this type.

It will be further understood that'while the bottom plate 3 has been shown and described asprovided with the elongated perfo.- rations` 7, and the upper plate with the uniform concentric openings, the same may be readily reversed without departing from the present invention, which resides entirely in the relative proportions and arrangements of the perforations in the cooperating plates;

I claim;

1. A strainer including a pair of perforated plates superimposed upon each other, thev perforations of said plates being circumferentially aligned, the perforations'in one of said plates being circumferentially elongated and formed in groups of circumferential rows, the openings of the inwardlysuccessive rows of each group being gradually reduced in length, and the openings of the correspond; ing rows of each group being of substantially equal area. y

2. A strainer including al pair of perforated plates superimposed upon each other, the perforations of said plates being circumferentially aligned, the perforations in one of said plates being circumferentially elongated and formed in groups of circumferential rows, the openings of the inwardly successive rows of each group being gradually reduced in length, and the openings of the corresponding rows of each group being of substantially equal area, said openings being radially disaligned. y

3. yA strainer including a pair of perforated plates superimposed upon each other, the

perforations of said plates being oiroumfer entially aligned, theperforations in one of said plates being oiroumferentially elongated and formed in groups of circumferential Y rows, the openings of the inwardly succes'- sive rows of each group being gradually reduced in length, and the openings of the corresponding rows of eaoh group beingof substantially equal area, said openings being radially disaligned, the perforations in the other of said plates being of less area than those of the first mentioned plate and aligned v circumferentially therewith.

4. A strainer comprising a pair of perforated plates superimposed upon eaoh other, the perforations of said plates being aligned circumferentially, Athe openings in one of said plates being elongated cireumferentially to provide slots, whereby to provide a substantially uniform area of opening through the plates irrespective of the relative position of the plates.

5. A strainer comprising a pair of perforated plates superimposed upon eaoh other, the perforations of both plates being aligned ciroumferentially, the perforations in one of said plates being elongated oiroumferentially to provide arcuate slots, and the perforations in the other of said plates'being of less area than those of the other plate and of uniform area and spacing whereby to provide a substantially uniform area of opening through the plates, irrespective of the relative position of the plates.

In testimony that I claim the foregoing I have hereunto set my hand at Milwaukee, in the county of Milwaukee and State of Wisconsin.

RICHARD G. MARTER. 

